An image sensor provides a grid of pixels, such as photosensitive diodes or photodiodes, reset transistors, source follower transistors, pinned layer photodiodes, and/or transfer transistors, for recording an intensity or brightness of light. Each pixel responds to the light by accumulating charge carriers (such as electrons and/or holes) generated by the light when the light passes into a silicon layer. The more light, the more charge carriers are generated. The charge carriers are measured by sensors and the measurements are then used by other circuits to provide color and brightness information that can be used for suitable applications, such as digital cameras. Common types of pixel grids include a charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) image sensor.
In semiconductor technologies, backside-illuminated sensors are used for sensing the amount of light projected toward the back-side surface of a substrate. The sensors, however, are formed on the front side of the substrate. Thus, light must pass through the substrate to reach the sensors. The light can pass through the substrate to reach the sensors, but some of the light is scattered while passing through the substrate. The scattered light reaches neighboring pixels and their corresponding sensors causing crosstalk between various sensor signals.